Phosphorus

Test Code

PHOS

Alias/See Also

Epic: LAB113

Phosphate
PO4
Inorganic Phosphorus

Preferred Specimen

Specimen Type: Serum
Collection Container: Serum gel
Specimen Volume: 3 mL

Minimum Volume

0.5 mL

Other Acceptable Specimens

Specimen Type: Plasma
Collection Container: Green top (Lithium heparin)

Instructions

Centrifuge and separate cells after clot formation and within 4 hours of collection.
Indicate specimen type on the label.

Transport Container

Plastic vial

Specimen Stability

Room temperature: 24 hours
Refrigerated: 4 days
Frozen: 1 year

Methodology

Phosphomolybdate

Setup Schedule

Daily

Report Available

Same day

Reference Range

0 - 1 years:	4.8 - 8.2 mg/dL
1 - 4 years:	3.8 - 6.5 mg/dL
4 - 7 years:	4.1 - 5.4 mg/dL
7 - 12 years:	3.7 - 5.6 mg/dL
12 – 14 years:	3.3 – 5.4 mg/dL
14 – 16 years:	2.9 – 5.4 mg/dL
16 – 18 years:	2.7 – 4.7 mg/dL
18 – 150 years:	2.3 – 4.7 mg/dL

Clinical Significance

The majority of the body phosphorus (80 – 85%) is present in the bones as hydroxyapatite. The remainder is present as inorganic phosphorus and phosphate esters. Calcium and phosphorus in serum usually exhibit a reciprocal relationship. Increased serum phosphorus may occur in hypervitaminosis D, hypoparathyroidism, and renal failure. Reduced serum phosphorus levels are seen in rickets (Vitamin D deficiency), hyperparathyroidism and Fanconi's syndrome.

Performing Laboratory

Inova Laboratories

2832 Juniper Street

Fairfax, VA 22031

Last Updated: April 14, 2023
Last Review: N. Wolford, April 14, 2023

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.